The present invention relates to a discharge assembly for controlling the discharge of material from a vessel, and to stator and rotor members employed to form such assembly. The present invention particularly relates to such discharge assembly and stator and rotor members formed of fireproof refractory ceramic material for controlling the discharge of molten metal from a metallurgical vessel. The present invention still further relates to such assembly and members wherein one of the members includes a structure forming a sliding seal with the other member, particularly by a cylindrical sliding surface, and further particularly by an exterior cylindrical sliding surface.
In such assembly, the stator member is an elongated member mounted to extend through the wall of the vessel and has therein a central longitudinal discharge passage opening at an outlet exterior of the vessel. An inlet end of the stator member has therethrough at least one lateral opening. The rotor member extends into the interior of the vessel and has an inner end having therethrough at least one lateral opening. The inner end of the rotor member is coupled to the inlet end of the stator member so that the rotor member is movable axially and/or rotatably relative to the stator member to bring the respective lateral openings thereof into and out of alignment, thereby to control the discharge of molten metal through the assembly.
DE-C1 40 32 084 discloses such an assembly of fireproof refractory ceramic sealing stator and rotor members. The stator member is embedded in and extends through the wall of a metallurgical vessel, for example to contain molten steel. The rotor member is arranged along the same axis of the stator member and extends upwardly out of the vessel. The inner end of the rotor member has a projection fitting into a cylindrical recess of the stator member. Complementary surfaces of the two members thus form sliding sealing surfaces, for example cylindrical sliding sealing surfaces. In principle, the rotor member could have therein the cylindrical opening or recess into which extends a cylindrical projection of the stator member. A drive rod interlocks with the rotor member and extends upwardly from the vessel and is coupled to a rotational drive device. Rotation of the rotor member by the drive device rotates the rotor member relative to the stator member such that lateral openings in the two members can be brought into and out of alignment, thereby controlling the discharge of molten steel from the vessel. Such vessel, for example a tundish, or other discharge or distribution vessel, may be employed for continuous casting, such that the outlet end of the stator member is submerged in molten steel in a casting mold and discharges molten steel thereinto. Thereby, the molten steel is protected from ambient air and surrounding atmosphere. In such known arrangement, the stator and rotor members are fireproof refractory ceramic members and are made from particular such materials. The formation of such members requires relatively expensive molds for their manufacture to be able to produce the members with sufficient precision, particularly at the complementary sliding sealing surfaces.